This invention is directed to systems for improving the productivity of operator-supervised industrial machines, such as systems of the type disclosed in U.S. Pat. No. 4,017,831 for N/C MACHINE PAGING, STATUS AND REPORT SYSTEM, issued Apr. 12, 1977, by Jansey D. Tieden and Forrester E. Woodruff, Jr.
While the herein-disclosed embodiment of the invention is directed to a system for use with N/C machines, it will be appreciated that the invention has utility as a support system for other types of industrial machines. In general, the invention is useful in conjunction with operator-supervised industrial machines that are arranged close together within a given plant area, and that are operated in an environment characterized by a high level of audible noise and limited operator visibility, such that audible and visual communication between the operator and support personnel is very difficult, if not possible, and in an environment characterized by the presence of high level electrical noise due to stray electromagnetic fields such that many common forms of electrical signal communication are unsatisfactory. As discussed more fully in the above referenced U.S. Pat. No. 4,017,831, the disclosure of which is incorporated herein by reference, these and other difficulties in monitoring the performance of N/C machines led to the development of the system disclosed in that patent for enabling the machine operator to effectively call for support personnel, such as tool kitters, supervisors, etc., immediately when needed, and provide performance monitoring capability, such as real time knowledge of machine status, and compilation of historical operating data for each machine. While a paging, status and report system constructed in accordance with the disclosure in U.S. Pat. No. 4,017,831 has served its intended purpose in markedly improving the productivity of a plurality of N/C machines, the implementation and online operation of the prior system has revealed some shortcomings.
One of these shortcomings is attributed to the overall architecture of the computer network employed in the prior system. As disclosed in the above cited U.S. patent, the prior system used one central computer for collecting data and for operating the various display devices and input/output terminals. Thus, a failure of the central computer would cause the entire system to shut down.
Another practical, but perplexing, difficulty was encountered in the installation and maintenance of the prior system. Because of the architecture of the system, input modules for each N/C machine require separate cables (a set for each N/C machine module), extending from the numerous machine modules to the central computer in a remote control room. Moreover, each visual paging board of the system required separate, multiwire cabling between the central computer in the control room and the plurality of paging boards disposed at various locations throughout the shop area. As a result, the prior system required a very substantial amount of wiring between its variously located components, thereby rendering the system expensive to install, both in terms of material and labor, and costly to maintain.
Even apart from the cost of the additional wiring there are numerous situations in which existing conduits for routing wiring and cables to and from the N/C machines are already filled to capacity and will, at best, accommodate only a limited amount of additional control cabling for installation of a system of the above-characterized type. Such limited cabling capacity severely constrains the use of the prior machine support system.
In addition to the above, other shortcomings of the existing system include its susceptibility to total system shutdown upon the occurrence of certain hardware failures at the operator controlled input modules; a limitation on the expansion of the system to accommodate additional machines and in general a lack of flexibility; and, the inability of the prior system to automatically diagnose and flag specific hardware component failures.
Accordingly, an object of the present invention is to provide an industrial machine paging, status monitoring and report compiling system using a computer network design that facilitates the transmission of data between the operator-controlled imput modules located on each machine and the various computing, visual display, permanent record storage and printout devices.
Another object of the invention is to provide such a system in which the computer network is configured so that the system is tolerant of certain component failures. In other words, a malfunction of certain of the system components will not necessarily cause the entire system to shut down, rather the system will continue to operate in a limited but useful capacity.
A further object of the invention is to provide such a system with flexibility in terms of being readily expanded, or reduced, to accommodate a greater or lesser number of monitored machines.
Still a further object of the invention is to provide such a system with the capability of automatically detecting and signalling a hardware failure within certain components of the system.